1. Technical Field
The invention relates to a display device packaging method and a display device and, in particular, to an OLED display device packaging method and an OLED display device.
2. Related Art
Organic light-emitting diodes (OLED) have several advantages such as self-luminous property, high brightness, high contrast, less volume, less power consumption and fast response, and therefore are gradually applied to various display devices, such as an OLED display device. Although the active matrix type of the OLED display device is made by a more complicated process with the higher cost, it is suitable for the large-scale and high-definition full color display with a large amount of information and therefore has become the mainstream of the OLED display device.
In the conventional packaging method for the OLED display panel, a glass adhesive (such as a fit adhesive) is used to block air and watery vapor from entering into the display panel and thus to avoid the damage of the display panel. The said packaging method includes the steps of: coating the edge of a cover plate 11 with a frit F as shown in FIG. 1A; glazing the frit F by using a laser pre-sintering process; covering the cover plate 11 and the fit F with a back plate (not shown); and implementing a laser sintering sealing process to melt the frit F again to seal the cover plate 11 and the back plate. Accordingly, the packaging process of the display panel is completed.
In the above-mentioned step of glazing the frit by the laser pre-sintering process, a laser beam is emitted to a start zone SZ of the frit F and then scans for a cycle to go back to the start zone SZ. However, a curved gap U will be generated in the start zone SZ as shown in FIG. 1B, resulting in the failure of the following laser sintering sealing process. For example, the gap U causes a loose sealing effect to the display panel.
The gap U is generated because the frit F in the start zone SZ is heated and cooled unevenly due to the different duration of the laser scanning and thus the temperature distribution of the fit F becomes uneven. In FIG. 1B, the left portion of the frit F in the start zone SZ is heated for a longer duration and thus glazed, while the right portion of the fit F in the start zone SZ is heated for a shorter duration and thus not glazed. The different changes of the frit F in the start zone SZ cause the thermal stress causing the break to the connecting interface between the glazed and unglazed portions of frit F, and the gap U is thus generated.
Therefore, it is an important to provide a display device packaging method and a display device so as to avoid generating the curved gap during the pre-sintering process and therefore the yield of the display device packaging method can be enhanced.